Correlation of syntaxin-1 and SNAP-25 clusters with docking and fusion of insulin granules analysed by total internal reflection fluorescence microscopy.

AIMS/HYPOTHESIS: The interaction of syntaxin-1 and SNAP-25 with insulin exocytosis was examined using the diabetic Goto-Kakizaki (GK) rat and a total internal reflection fluorescence (TIRF) imaging system. METHODS: Primary rat pancreatic beta cells were immunostained with anti-syntaxin-1A, anti-SNAP-25 and anti-insulin antibodies, and then observed by TIRF microscopy. The real-time image of GFP-labelled insulin granules motion was monitored by TIRF. RESULTS: The number of syntaxin-1A and SNAP-25 clusters, and the number of docked insulin granules on the plasma membrane were reduced in GK beta cells. When GK rats were treated with daily insulin injection for 2 weeks, the number of syntaxin-1 and SNAP-25 clusters was restored, along with the number of docked insulin granules. The infection of GK beta cells with Adex1CA SNAP-25 increased the number of docked insulin granules. TIRF imaging analysis demonstrated that the decreased number of fusion events from previously docked insulin granules in GK beta cells was restored when the number of docked insulin granules increased by insulin treatment or Adex1CA SNAP-25 infection. CONCLUSIONS/INTERPRETATION: There was a close correlation between the number of syntaxin-1 and SNAP-25 clusters and the number of docked insulin granules, which is associated with the fusion of insulin granules.

[A case of brain stem infarction with bilateral hearing loss].

The study case was a 66-year-old man who had bilateral neurosensory hearing impairment due to brain stem infarctions. He noticed mild hearing loss, frequent vertigo and tinnitus. About one month later, his hearing took a sudden turn for the worse, and he suffered from dysarthria, dysphagea and abasia. Neurological examination revealed pseudobulber palsy, left hemiparesis, cerebeller ataxia, disturbance of pain and temperature sensation on the right face and left side of the body. Brain stem auditory evoked potentials (BAEPs) showed a delayed small wave V with the abscence of previous waves on the right side and no significant waves on the left side. Brain magnetic resonance images (MRI) revealed infarctions in the bilateral middle cerebellar peduncles, including in the right lateral portions of pons, and the right lower pontine base. We believe that not only peripheral, but also central auditory pathways adjacent to infarctions were damaged. Magnetic resonance angiography (MRA) showed severe stenosis or occlusion of left vertebral artery and basilar artery. We concluded that hypoperfusion of the vertebrobasilar artery territories caused ischemia of the cochlear nerve and the auditory tracts in the brain stem, which resulted in bilateral hearing loss.

A case of pharyngolaryngeal stenosis in Behçet's disease.

A rare case of pharyngolaryngeal stenosis in Behçet's disease is reported. A 44-year-old female who had Behçet's disease for 13 years complained of dysphagia and dyspnea, and was referred to our hospital for treatment in May 1988. The bilateral meso-hypopharyngeal walls were swollen, and the epiglottis was edematously folded, occluding the larynx. Epiglotectomy and thyrohyoidpexia were performed, with dysphagia and dyspnea disappearing after the operation. Two years after the operation, dysphagia and dyspnea recurred because of two stepped cicatricial stenoses at the mesopharynx. An enlargement operation, incising the pharyngeal cicatricial tissue bilaterally and covering raw surfaces with free skins and the pedunculated cervical flap, was performed. Colchicine, corticosteroid, and tranilast (anti-allergy drug) were administered to prevent re-stenosis. Stenosis was not observed for 10 months after the second operation. Two cases undergone surgical interventions have been reported, and this is the first case reporting long term result of the surgical procedure. Because the skin and mucosa of patients with Behçet's disease shows hyperreactivity to stimuli, the choice of surgical procedure is controversial and recurrence of stenosis is possible.

An ameloblastoma-like neoplasm of the buccal mucosa. Report of a case.

A case of an unusual neoplasm of the buccal mucosa nearly identical to an ameloblastoma is reported. The tumor probably arose from the overlying squamous epithelium in the vicinity of the parotid duct.